[1] The team, owned by his father, decided to move up to the Indy Pro Series in 2006, but Sean was forced to miss the first three races of the season as he was not yet the league-mandated 18 years old.

[2] In the Iowa Speedway race Sean suffered a heavy crash and the team's car had to be sent back to the manufacturer Dallara in Italy for repairs.

Sean made three starts at the end of the season for Playa Del Racing as the team ran in cooperation with Guthrie.

Until his suspension in April 2009, he drove for his father's team Guthrie Racing along with teammates Alistair Jackson and Jesse Mason.

[4] After participating in dirt track racing throughout 2010, Guthrie again returned to Indy Lights for the season finale at Homestead with Andersen, finishing 10th.